I don't know what to do about that, I don't have much add-ons, I removed almost every of them.I have Adblock, A YT downloader and Greasemonkey.Where do this problem comes from ? Not only Firefox takes too much RAM but there are 2 of them.

Here is a pic of the task manager. Both Firefox takes around 500mo each.

SolidStateScouter wrote:Also I can't use safe mode, when i use the firefox -safe-mode commande, it launch regular firefox.

Do you mean that in Safe Mode add-ons aren't disabled ?

The add-ons that you have installed - especially AdBlock Plus - are known to use a lot of CPU.You might consider to remove AdBlock Plus and use uBlock Origin instead.

Another reason could be if you are using Multi process (e10s)

You can check whether you have this feature turned on as follows :

• '3-bar' menu button => ' ? ' button => Troubleshooting Information• type 'about:support ' (without the commas) in the address bar and press Enter/ReturnIn the first table on the page, check the row for 'Multiprocess Windows' and see whether the number on the left side of the fraction is greater than zero. If so, you are using e10s - otherwise it should read : 0/1 (Disabled).

If you are using e10s:You could turn it off as follows :Type in the address bar 'about:config' (without the quotation marks)(promise to be careful, if asked)Type and search for the preferences :'browser.tabs.remote.autostart' (without the quotation marks)and set it's value to 'false''browser.tabs.remote.autostart.2' (without the quotation marks)and set it's value to 'false'

Note: the exact name of the preference may vary, but it will start with browser.tabs.remote.autostart

Well I hav this problem since a while now, so restarting isn't an option anymore ^^.

Indeed there is 3 firefox, I didn't noticed.I disabeld the Multi Process thing, I set the browser.tabs.remote.autostart2 to false, it was on true, I had "1/1 (default)" in the troubleshooting table.I also installed origin ublock and removed adblock. I'll see now how it goes after I restart Firefox.

edit : i've found a way to start Firefox without addons in the same 'troubleshooting' page with the table. Now I still have 2 process who are ~150000 kb and ~110000kb (it goes up and down between 60k and +100k kb)

SolidStateScouter wrote:Also I can't use safe mode, when i use the firefox -safe-mode commande, it launch regular firefox.

Firefox has to be closed first (or used with the -no-remote switch, & a different Profile) for "firefox -safe-mode" to open in Safe Mode. Otherwise it will simply open a new "regular" window in the existing Profile.

Quit FF.Check Task Manager.Verify that there are no "firefox.exe" processes hanging about.

At that point, "firefox -safe-mode" should work as expected.

I disabeld the Multi Process thing

Now I still have 2 process who are ~150000 kb and ~110000kb (it goes up and down between 60k and +100k kb)

If you disabled Multi Process, you should only be seeing 1 firefox.exe.If there are more then 1, then MP is not disabled, you are running multiple instances of FF, or one of those firefox.exe are hung in memory (never Quit completely).

If you have Multi Process enabled, then it is expected for there to be more then 1 firefox.exe.